Issue registering old cisco device

I used to register each of Cisco VG224 FXS port as freepbx extension configuring each port like:

dial-peer voice 7111 pots
destination-pattern 7111
authentication username 7111 password 7 13411E022D2B56787F60
port 2/0

sip-ua 
 registrar ipv4:192.168.1.200 expires 300

Now I’m doing the same for a ISDN phone connected to an old Cisco 1760 VIC2-2BRI with the same syntax but I get this warning (and failed registration):

[2024-05-07 19:09:52] WARNING[2602]: pjproject: <?>: sip_transport.c Dropping 449 bytes packet from UDP 192.168.1.198:58350 : PJSIP syntax error exception when parsing 'From' header on line 3 col 12: PJSIP syntax error exception when parsing 'To' header on line 4 col 10: PJSIP syntax error exception when parsing 'Contact' header on line 11 col 15

Any idea ?

Turn on pjsip logger and show the REGISTER request sent from the 1760.

It looks like it is always the same point in the URI or name-addr construct, and near the beginning. I’d say either trying to use tel: URIs or an illegal character, e.g. unescaped @ in the user part. We need to see what is actually received.

The position of the error is always the same distance from the end of the header name.

I’m not sure if tel: causes a syntax error, or something more specific.

Thanks,
Registration issue is dued to a test pjsip trunk pointing to Cisco router that, despite it was disabled, caused problems.
Trunk deleted, registration is OK.
Those warnings are still present but all is working fine.